Harpswell puts brown tail moth study before Town Meeting

HARPSWELL — As spring approaches, voters will have the opportunity to approve new research on the local browntail moth population.

According to a draft warrant article for Town Meeting on March 10, voters will decide whether to allocate just over $9,500 for the University of Maine to conduct studies on browntail moths, and ways to naturally reduce their number in Harpswell.

The warrant article follows a special Board of Selectmen workshop last November, where Eleanor Groden, a professor of entomology at UMaine, discussed her work as director of the university’s Browntail Moth Research Project. The program is conducted in collaboration with the Maine Forest Service, and aims to pinpoint the cause of the insect’s spread throughout Maine and eco-friendly ways to squelch it.

Hairs from browntail moth caterpillars can cause allergic reactions in some people, ranging from rashes to serious respiratory problems, which has made their regional surge in recent years problematic.

If the warrante article passes, Groden and her students will conduct a year of work in Harpswell, taking samples of moth nests, testing different eco-friendly pest control techniques, and composing a report to the town.

Harpswell’s pesticide ordinance, which was revised in March 2016, prohibits spraying within 25 feet of the shoreline to protect marine life. Aerial spraying of chemicals in town is also banned.

As a result, Mary Ann Nahf, chairwoman of the town’s Conservation Commission, instructs residents to clip browntail nests from trees in the winter and dunk them in soapy water to prevent springtime hatching.

Nahf said an increasing number of town residents in recent years have reached out to the commission regarding what to do about moth nests. In addition to the clipping and soaking method, homeowners can also hire licensed applicators to inject trees on their property with pesticides.

Stem injection, however, is only allowed in Harpswell with a waiver, which requires a town hearing to be granted. For the past two years, Nahf said, the town has seen the same properties applying for permission.

This year, she said, the ordinance will be amended to add a waiver renewal, allowing licensed applicators to renew waivers approved the previous year without a new hearing.

“This should free up time for the arborists during a very busy season,” Nahf said.

At the selectmen’s Feb. 8 meeting, Nahf spoke on behalf of the commission and voiced the group’s support for the warrant item and associated research.

For many people in Harpswell, she said, treating nests independently, within the parameters of the pesticide ordinance, is not ideal.

“The problem is, those remedies are either prohibitively expensive for many of our residents – stem injection for example – or practically impossible, (like) clipping in mid-winter because so many of the nests are too high to reach safely,” she said.

According to Groden’s proposal to the town, if voters approve the funds, she will travel to Harpswell in late March to evaluate the density of moth populations at different sites.

The researchers will take samples from webs at each site back to the university lab in Orono, set them up to allow caterpillar emergence, and examine them to determine survival over the winter, parasitism and disease level.

They will also return to Harpswell to monitor caterpillar emergence and feeding activity at each of the designated sites.

In mid-May, the team will then conduct field trials to evaluate the efficiency of at least three organically certified and biorational options for caterpillar control with a licensed pesticide applicator. In November, one option Groden highlighted was a naturally-occurring fungal pathogen in some moth populations, that, when weather is favorable, multiplies and kills larvae in the nest.

Following the field tests, the team would assess the impact of the treatments on the browntail population and their natural enemies, collect pupation nests and monitor them in the lab, and re-visit the treatment sites to monitor the presence of winter webs in Feb. 2019.

Groden and her team will give the town of Harpswell periodic updates on the research, a final report, and arrange a public presentation for the community after research is complete.

At the selectmen’s meeting, Nahf went on to say that she and other commission members think Groden’s work will be cost-effective, and they are willing to help if necessary.

“Widespread spraying has been tried in the past and has resulted in killing of marine life, (which is) not a good option for our community,” Nahf said. “We need to better understand the geographic distribution and severity of the infestation throughout Harpswell and hopefully develop new remedies to address the problem.”